Antitheft lock key safety latching devices

ABSTRACT

The safety device comprises a resilient member which is pivoted to the fixed body of the lock of an antitheft device, externally thereof each end of the resilient member engaging respectively an abutment element of said fixed body and an abutment element of a rotary cylinder plate of the lock, the expansion of said resilient member causing said cylinder and therefore the antitheft device to be resiliently restored to a position spaced angularly a few degrees from the cylinder position permitting the withdrawal of the key, whereby the user must compulsorily exert a non-negligible effort for restoring the key and cylinder to the withdrawal position.

Unite States Patent Societe DExpiaitan'on Des Brevets NeirnanNeuilly-sur-Seine (Hauts de Seine), France [73] Assignee [32] PriorityMar. 10, 1969 [33] France [31 1 69 06579 [54] ANTITHEFI LOCK KEY SAFETYLATCHING 431, 432, 447, 441, DIG. 62, DIG. 54; 200/44, 42, 61.54,61.67

[ 56] References Cited UNlTED STATES PATENTS 3,529,456 9/1970 McWilliams70/447 FOREIGN PATENTS 678,167 8/1952 Great Britain 70/447 850,8669/1952 Germany 70/447 1,082,156 3/1954 Germany 70/389 PrimaryExaminerlan A. Calvert Assistant Examiner-Robert L WolfeAttorney-Stevens, Davis, Miller and. Mosher ABSTRACT: The safety devicecomprises a resilient member which is pivoted to the fixed body of thelock of an antitheft device, externally thereof each end of theresilient member engaging respectively an abutment element of said fixedbody and an abutment element of a rotary cylinder plate of the lock, theexpansion of said resilient member causing said cylinder and thereforethe antitheft device to be resiliently restored to a position spacedangularly a few degrees from the cylinder position permitting thewithdrawal of the key, whereby the user must compulsorily exert anon-negligible effort for restoring the key and cylinder to thewithdrawal position.

ANTITI'IEFT LOCIK KEY SAFETY LATCHING DEVICES The present invention isconcerned with safety-lock antitheft devices of the type mounted on mostmodern motor vehicles, and notably with devices of the type wherein thewithdrawal of the key is attended automatically by the engagement ofalock bolt into a member to be locked, for example the steering columnofthe vehicle.

It is known that a key cannot be removed from, or inserted int0, acylinder lock, whether of the pin tumbler or disc tumbler type, unlessthe pins or the discs register exactly with the recesses providedtherefor in the fixed body of the lock.

In certain countries there is a legal obligation to provide anadditional safety feature in antitheft locks of this character with aview to prevent the untimely withdrawal of the key controlling theantitheft device when this key constitutes at the same time a detachableabutment member for locking the lock bolt.

It is the essential object of the present invention to provide a devicecapable of providing a satisfactory solution to this problem.

The device applicable to antitheft devices comprising a cylinder lockhaving a fixed lock body and a rotary inner cylinder provided with anantitheft control plate and actuatable by means of a notched key,includes a resilient member pivoted to the fixed lock body, externallythereof, said fixed body and said cylinder plate being each providedwith a stop engageable by one end of said resilient member,respectively, the expansion of said resilient member being adaptedresilient y to urge said cylinder and said antitheft control plate to aposition spaced a few degrees from the cylinder position permitting the.key withdrawal, whereby the driver of the vehicle is compelled to makea far from negligible effort for restoring the key and the lock cylinderto the position permitting this withdrawal.

The invention will now be described more in detail with reference to theaccompanying drawing illustrating diagrammatically by way of exampletypical forms of embodiment thereof. In the drawing:

FIG. 1 is a diagrammatic cross-sectional view showing the cylinder andthe fixed body of a conventional pin tumbler safety lock, the sectionbeing taken along the axis of a pin with the latter positioned inalignment with its two bore sections, thus permitting the withdrawal ofthe key;

FIG. 2 is another sectional view showing the same lock after thecylinder has been rotated a few degrees in the fixed body;

FIGS. 3 and 4 are cross-sectional views showing a known disc tumblercylinder, the sections being taken across one disc;

FIGS. 5 and 6 illustrate the lock cylinder of FIGS. 3 and 4 in the samepositions, respectively, according to one form of embodiment of theinvention, and

FIG. 7 is a view similar to FIGS. 5 and 6 but modified form ofembodiment.

The last three FIGS. of the drawing are external lateral views of thefixed body or similar element of the safety lock, assumed to be removedfrom the body of the antitheft device or from the body of the lock case.

Referring first to FIG. 1, the pin tumbler safety lock of conventionaltype illustrated therein comprises as usual a cylinder or plug 4 andradial pin tumblers, of which one is shown at 4 as being urged by aspring 2 towards the cylinder axis, the cylinder being adapted on theother hand to be engaged by a key 3 for rotating the cylinder inside afixed lock body 5.

In FIG. 2 the key 3 and therefore the cylinder 4 have been rotated inthe counterclockwise direction through a small angle, for example a fewdegrees; thus, the base of pin 1 engages the inner cylindrical surfaceof the cylinder-receiving bore of fixed body 5. Under these conditionsthe key 3 cannot be withdrawn since on the one hand the key edge iswedged against the inner end or point Ia of pin tumbler l, and on theother hand the base or outer end of pin I abuts against said cylindricalsurface.

In the case of a known type of disc tumbler cylinder lock as showing ashown in FIGS. 3 and 4 a small angular movement shown in FIG. 4 is alsosufficient for safety preventing the withdrawal of key 3. The force oflateral spring 2 urging the disc 4a 0utwards assists in causing thefrictional engagement between the key and the various central recessesof the discs.

In each one of the two cases contemplated hereinabove it is clear that aresilient abutment is created a few degrees before attaining theposition permitting the free withdrawal of the key.

It is therefore definitely necessary to provide some means forovercoming this elastic resistance when moving the key to the positionspermitting the key withdrawal, which are shown in FIGS. 1 and 3. Thismeans is constituted by the device of this invention, as illustrated inFIGS. 5, 6 and 7.

In the device shown in FIGS. 5 and 6, a plate 6 solid with the cylinderand then rotatably rigid with the key 3 comprises a peripheral stud orprojection 7, and the fixed body 5 of the lock is formed with aprojection 9 and carries an hairpin spring 8 securecl'at its elbow to apin 11; this spring 8 engages with one arm stud 7 and with the other armthe projection 9, thus constantly urging the cylinder unit to one of thepositions shown in FIGS. 2 and 4, corresponding to FIG. 6. Thus, it isclear that to restore the key 3 in the position shown in FIG. 5 the usermust exert an effort sufficient to compress the hairpin spring 8 untilthis position is attained, so that the key can be removed from the lock.

Thus, in the position shown in FIG. 6 a resilient abutment device iscreated which, as shown in FIGS. 2 and 4, counteracts the rapid anduntimely withdrawal of the key.

FIG. 7 illustrates a modified form of embodiment of the device shown inFIG. 5, wherein in lieu of the hairpin spring 8 a coil compressionspring 8' is used this spring 8' reacts against a fixed element 12carried by the outer surface of the lock body 5 and constantly urges anarm 10 pivoted to the same body about a pin II, the outer end of arm 10transmitting the force of spring 8' cylinder plate 6.

lf the antitheft device comprises in the known fashion a switchcontrolling the ignition and starter motor of the vehicle, thesameprinciple as set forth hereinabove may be used for restoring thelock cylinder from the Start" position to the Ignition position.

Although the present invention has been described in conjunction withpreferred embodiments, it is to be understood that modifications andvariations may be resorted to without departing from the spirit andscope of the invention, as those skilled in the art will readilyunderstand. Such modifications and variations are considered to bewithin the purview and scope of the invention and appended claims.

What I claim as new is:

1. A safety device for preventing the untimely withdrawal of the keyfrom antitheft devices, notably in a motor vehicle, this antitheftdevice comprising a lock having a fixed body and a rotary cylinderprovided with a plate for controlling the anto the stud 7 carried by thetitheft member by means of the key, wherein a resilient member ispivoted to the fixed body of the lock, externally thereof, said fixedbody and said cylinder plate carrying each an abutment element engagedby one end of said resilient member, respectively, the expansion of saidresilient member causing said cylinder and therefore the antitheftdevice to be resiliently restored to a position spaced angularly a fewdegrees from the cylinder position permitting the withdrawal of the key,whereby the user must compulsorily exert a non negligible effort forrestoring the key and cylinder to the withdrawal position.

2. Device as set forth in claim 1, wherein said resilient member is anhairpin spring.

3. Device as set forth in claim 1, wherein said resilient member is acoil compression spring associated with a pivoted arm.

4. Device as set forth in claim 1, wherein said antitheft devicecomprises a switch controlling the starting and ignition of the vehicleengine, the lock key permitting of restoring the lock cylinder from theStart" position to the "Ignition" posi- IIOII.

1. A safety device for preventing the untimely withdrawal of the keyfrom antitheft devices, notably in a motor vehicle, this antitheftdevice comprising a lock having a fixed body and a rotary cylinderprovided with a plate for controlling the antitheft member by means ofthe key, wherein a resilient member is pivoted to the fixed body of thelock, externally thereof, said fixed body and said cylinder platecarrying each an abutment element engaged by one end of said resilientmember, respectively, the expansion of said resilient member causingsaid cylinder and therefore the antitheft device to be resilientlyrestored to a position spaced angularly a few degrees from the cylinderposition permitting the withdrawal of the key, whereby the user mustcompulsorily exert a non negligible effort for restoring the key andcylinder to the withdrawal position.
 2. Device as set forth in claim 1,wherein said resilient member is an hairpin spring.
 3. Device as setforth in claim 1, wherein said resilient member is a coil compressionspring associated with a pivoted arm.
 4. Device as set forth in claim 1,wherein said antitheft device comprises a switch controlling thestarting and ignition of the vehicle engine, the lock key permitting ofrestoring the lock cylinder from the ''''Start'''' position to the''''Ignition'''' position.